Fixes for Palette mode

This patch fixes 2 issues in Palette mode:
1. More memory is needed in PALETTE_BUFFER for 444 video format.
2. A merge issue caused by
https://chromium-review.googlesource.com/#/c/333940/7

Change-Id: I2aedc7dfdfb6b66fbd600189ec6e1e2cc6120d40
diff --git a/vp10/decoder/decodeframe.c b/vp10/decoder/decodeframe.c
index fb292fd..8aa0027 100644
--- a/vp10/decoder/decodeframe.c
+++ b/vp10/decoder/decodeframe.c
@@ -1881,9 +1881,6 @@
             (xd->mb_to_bottom_edge >= 0 ?
              0 : xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));
 
-        if (plane <= 1 && mbmi->palette_mode_info.palette_size[plane])
-          vp10_decode_palette_tokens(xd, plane, r);
-
         for (row = 0; row < max_blocks_high; row += step)
           for (col = 0; col < max_blocks_wide; col += step)
             predict_and_reconstruct_intra_block(xd,
diff --git a/vp10/encoder/block.h b/vp10/encoder/block.h
index 295213f..582f3bc 100644
--- a/vp10/encoder/block.h
+++ b/vp10/encoder/block.h
@@ -64,7 +64,7 @@
 
 typedef struct {
   uint8_t best_palette_color_map[4096];
-  double kmeans_data_buf[4096];
+  double kmeans_data_buf[2 * 4096];
   uint8_t kmeans_indices_buf[4096];
   uint8_t kmeans_pre_indices_buf[4096];
 } PALETTE_BUFFER;